1. Field of the Invention
The present invention relates generally to devices for coupling or releasably attaching parts together, and specifically to a coupling for use in connecting or attaching two pipe ends, such as two pipe ends in a process, two hopper tees or other fittings via pipe or tube in a transportation vehicle or other related system.
2. Description of Related Art
In the field of pipe coupling, such coupling members, clamps and similar devices are used to connect the ends of pipes together. For example, in the area of dry bulk handling, such couplings or clamps are used to connect sections of pipe or hopper tees in connection with a bulk transportation vehicle. The use of these couplings ensures that external and/or hostile contamination does not occur, and, further, such couplings are used in the unloading of the material that is being transported, such as dry bulk powders, pellets and the like.
In the dry bulk industry, such tank cars are unloaded through valves positioned at the bottom of a material container. Further, in order to prevent cross contamination, the material container must be completely evacuated to ensure that varying material loads do not come in contact. In addition, in order to allow for appropriate adjustment of the coupling, some adjustment assembly should be used to allow for wear-and-tear and loosening of the clamping function of the coupling.
According to the prior art, and as seen in U.S. Pat. No. 5,540,465 to Sisk, a pipe, valve or tee coupler is disclosed. The coupler 30 includes two clamping arms 32, 34, and, at one end of each arm 32, 34 a hinge 40 integrally formed therewith. A bail lever 56 is attached to a mount 46. The walls of the clamping arms 32, 34 define a seat for a gasket 150, which will contact and seal against the pipe ends. An adjustable bail assembly 80 is pivotally attached to the bail lever 56 and includes a U-shaped bail 82 with opposed arms 84, 86. Each arm 84, 86 of the bail 82 terminates in a threaded portion 88, 90 and extends through a respective orifice on a pivot rod 92 extending through the lever 56. A pair of pivotal spacers 102, 104 are positioned on the rod 92 on each side of the lever 56, and these spacers 102, 104 are mounted to the bail lever 56.
The adjustment assembly of the Sisk patent includes a first tightening nut 106 engaged on threaded portion 88 above rod end 95, a second tightening nut 108 engaged on threaded portion 88 below rod end 95, a third tightening nut 110 engaged on threaded portion 90 above rod end 98 and a fourth tightening nut 112 engaged on threaded portion 90 below rod end 98. It is these tightening nuts 106, 108, 110, 112 and associated operational structure that form an assembly that allows for the adjustment of the bail 82 and its interaction with a boss 124 formed on the second end of claiming arm 34, specifically in a groove 125 formed therein. The coupler of the Sisk patent also requires planar extensions or ribs positioned on the various side walls of the clamping arms 32, 34 in order to engage specified pipe surfaces. U.S. Pat. No. 5,722,666, also to Sisk, is directed to a gasket for use in connection with the coupler 30 discussed above.
Couplings are used for connecting pipes, tees and other parts together, as is known in the art. There are many references that disclose couplers having various means for attaching two semi-circular shell arms, for use in connecting parts together. For example, such prior art coupling systems and mechanisms are disclosed in U.S. Pat. No.: 6,533,332 to Vitel et al.; U.S. Pat. No. 5,647,612 to Yoshida et al.; U.S. Pat. No. 5,415,435 to Colbert; U.S. Pat. No. 5,209,528 to Weh et al.; U.S. Pat. No. 5,104,153 to Corcoran; U.S. Pat. No. 5,018,768 to Palatchy; U.S. Pat. No. 4,311,248 to Westerlund et al.; U.S. Pat. No. 4,272,871 to Weinhold; U.S. Pat. No. 4,041,975 to Ames; U.S. Pat. No. 3,695,638 to Blakeley; U.S. Pat. No. 3,476,410 to Pastva; U.S. Pat. No. 3,113,791 to Frost et al.; U.S. Pat. No. 2,731,280 to Goodliffe et al.; and U.S. Pat. No. 957,695 to Marek. All of these couplings, while effective in coupling two parts together, such as the ends of two pipes, have many drawbacks.
One drawback of these prior art couplings is the lack of safety precautions that protect against tampering, removal or accidental opening. These couplings, as disclosed, are easily opened by an unauthorized person who simply has the means or tools to open the latching mechanism. For example, with respect to the coupling of the Sisk patent, even if the handle is secured to one of the coupling arms, an unauthorized person need only use the appropriate tools to loosen and remove tightening nuts 106, 108, and remove the bail, thereby gaining the ability to open the arms.
Another drawback to the prior art couplings is the difficulty of closing and locking the arms in operation, especially during the initial openings and closings of the coupling. Due to the rigidity of the bail or other lever or handle, the locking mechanism is inflexible and requires excessive force to open and close. Therefore, in using many of these prior art couplings, the user is required to utilize additional tools to actuate the handle and latch or unlatch coupling.
Yet another drawback of the prior art is the pinch point that occurs at the hinge joint of the coupling arms. Such a pinch point can damage the gaskets or packing of the coupled parts, and also applies undesirable forces and pressures during the coupling process. Still further, when the coupling is using a gasket or other sealing means seated within the arms of the coupling, the pinch point can also compress, break or tear the gasket, thereby rendering the seal ineffective.